In 1978, Bp. Timothy was appointed to succeed Bp. Iakovos (Garmatis) as Bishop of the Seventh District of Detroit in the United States of America. 15 March 1979 after the re-designation of districts as dioceses, he was enthroned as Bishop of the Diocese of Detroit.

On December 11, 1998, Bp. Timothy died in an Athens hospital following complications from asthma at 74 years old.

The funeral service was chanted on December 15, 1998 at the Church of the Assumption Kaisarianis presided over by Metropolitan New Smyrna Agathangelos. He was buried on December 15, 1998 in Kaisieriani Cemetery.